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Contralateral effects of eccentric exercise and delayed onset muscle soreness (DOMS) of the plantar flexors: Evidence of central mechanism involved / Suresh Marathamuthu
Get PDFPeripheral and central factors play important roles in the reduction of motor performance following a damaging eccentric exercise and delayed onset of muscle soreness (DOMS). Following this regime, contralateral limb could also be affected, however, the factors involved are inconclusive. The purpose of this study was to distinct contribution of peripheral and central factors following eccentric contraction and DOMS of the plantar flexors in both treated and contralateral homologous limb. Ten males (BMI = 25.08 ± 1.69 kgm-2; age = 28.70 ± 4.24 years) were randomly assigned to experimental (DOM) or control (CON). The DOM group was treated with a damaging eccentric exercise, while CON rested. Plasma creatine kinase concentration (CK), visual analogue scale (VAS), muscle stiffness, maximal voluntary contraction (MVC) and voluntary activation (VA) were measured at pre, post-10 min, -24, -48, -72 hour, on both treated and contralateral limb. After the exercise, CK increased up-to post-48 hour, while VAS up-to post-72 hour compared to pre. Importantly, MVC was reduced at all-time points with greatest drop at post-24 hour (-16%), while VA affected up to post-48 hour with greatest drop at post-10 minute (-7%). Interestingly, a ‘cross-over effect’ was observed in the contralateral limb when VAS, MVC, and VA were negatively affected following the same pattern (time line) as in the treated limb (-13% peak MVC drop; -3.5% peak VA drop). These findings suggest a substantial central contribution to the drop in force especially immediately after the exercise and to a lesser extent the later part of DOMS in both treated and contralateral limb
The determinants of tax non-compliance: Evidence from Malaysia / Azman Gul Zaman Khan
Get PDFTax non-compliance is an act of disobeying the tax laws provided by the legislation either intentionally or unintentionally. The objective of this study is to examine the relationship of four independent variables; tax knowledge, ethics, government quality and change in government to the dependent variable; tax non-compliance. The research framework of this study is developed based on five variables and employed theory of planned behavior. Four hypotheses are tested based on the research framework. The research instrument of this study is structured questionnaire. The questionnaires are distributed to taxpayers in Klang Valley. A total of 415 samples were collected from taxpayers through two sampling techniques which are purposive sampling and snowball sampling.
Based on the analysis, three independent variables; ethics, government quality and change in government have significant impact to the dependent variable; tax non-compliance while the remaining independent variable; tax knowledge has no significant impact to the dependent variable; tax non-compliance. Next, the study addresses some limitation to the study in which the sample size that represents the whole population of individual taxpayers in Malaysia may not be sufficient to generalize the whole taxpayers. Hence, suggestion for future research is to increase the sample size so that the future research able to generalize the whole population and able to come out with a stronger regression model
Lexical borrowings in the use of Singlish by bloggers / Vilashiiney K. Panneerselvam
Get PDFSingapore English is among the many new Englishes which have emerged across the world. It is divided into two forms; Standard Singapore English and Colloquial Singapore English also known as Singlish. The colloquial variety of this English is viewed as crippling the Standard English and has led to the initiation of the Speak Good English Movement by the Singapore government. Recently, linguists such as Wee (2014) have stated that Singlish should be allowed to be used as it reflects the true cultural identity of Singaporeans and this has led to the initiation of the Speak Good Singlish Movement. Singapore’s bilingual education system where students learn English and a designated mother tongue simultaneously may have caused ‘Singlish’ (Rubdy, 2001). However, regardless of its status, Singlish is vastly used among Singaporeans, especially on social media. This research seeks to investigate the types and indigenisation features of lexical borrowings found in the use of Singlish by Singaporean bloggers in written form. Blogging is becoming a trend of web communication and believed to be an ideal medium to analyse lexical borrowings because the written language in blogs is casual and very similar to spoken conversations. Blogging is also an asynchronous type of computer-mediated-communication which allows participants to interact according to their preferred time and place. This indicates that bloggers have made a conscious decision to use Singlish vocabulary in their blogs, which also reflects their true cultural identity. The types of lexical borrowings found in this study will be analysed using Winford’s (2003) model which is a simplified version of Haugen’s (1950) groundbreaking work. Meanwhile, the indigenisation features will be analysed according to Baskaran’s (2005) categorisations. Haugen's (1950) types distinguish lexical borrowings according to phonemic and morphemic level of substitution and importation while Baskaran's (2005) indigenisation features distinguish lexical borrowings according to their semantic relationships. This corpus-based study presents one possible way to analyse language contact phenomena via lexical level analysis and provides two different approaches to analysing lexical borrowings. The findings from this study are expected to present additional knowledge on colloquial language and contribute to the existing Singlish vocabular
Chemical variability in volatile oils of Bentong ginger: A chemometric study / Farah Syuhaidah Ahmad Jahiddin
Get PDFThe volatile oil of ginger (Zingiber officinale) possesses various pharmacological properties corresponding to its chemical compositions, which in turn, depends on its source material and preparation method. In this study, preliminary experiments were carried out to investigate the variations in volatile oil of ginger prepared based on different method (dry/fresh samples), extraction duration and size reduction process (grate/slice samples). The ginger volatile oil yield can be quantitatively improved by using a fresh sample with grated form and a longer extraction cycle. Gas Chromatography-Mass Spectrometry (GC-MS) was conducted and the chromatogram profile was subjected to Principal Component Analysis (PCA). Results show that extract of fresh samples was predominated by the presence of monoterpenes while sesquiterpenes were more profound in the grated samples; meanwhile, the extraction duration demonstrated a direct and inverse relationship on monoterpenes and sesquiterpenes. As the optimum extraction procedure has been determined, the variability in the volatile components was further explored using pattern recognition tools. The results revealed a tendency for the volatile oil components to cluster, probably due to the geographic origin of the ginger material, therefore highlighting that the terpene components in Bentong ginger could be used to differentiate it from other commercial gingers. The overall findings demonstrate that different sample preparation methods and geographical origin will affect the quantity and/or quality of ginger extract obtained
Development of bio-based 2T engine oil in marine engine application / Babooraman Shanmuganathan
Get PDFTwo-storke enginers are simple and lightweight two-cycle spark ignition engine with no oil sump is needed. The use of bio-based lubricants was analyzed to replace commercial mineral and synthetic-based lubricants. Lubricants were prepared by mixing three components of oil which comprise of base oil, additives, and solvent. In this research, four samples of base oil had been prepared with a different weight ratio of the PFAD-NPGester and Type II mineral. Then each of the simples were added with a similiar weight ratio of additives and solvent. A commercial lubricant was used as areference lubricant to be compared with samples prepared. A viscometer was used to determine the viscosity index and density of each sample and reference lubricant. Next, afour-ball tribo-tester was used to evaluate friction and wear prevention characteristics ineach sample and rreference lubricant. Finally, an idle operation mode had been conductedon a two-stroke brush cutter engine to determine the effect of reference lubricant and bio-based lubricant towards carbon deposition on the spark plug. Lubricant sample B coptrises a 40% weight percentage of PFAD-NPG ester and a 60% weight percentageof Type II mineral oil. Sample B had exhibited the highest viscosity index of 154.4 compared to other samples and reference lubricants with the lowest viscosity index of 129.5. This enables it to form a thick lubricantion film between moving surfaces. Based onfriction evaluation results, it can be seen that Sample B has recorded the lowest COF value compared to reference lubricant. Throught the WSD analysis conducted, sample B was record to have the lowest WSD value is 580.69mm compared to the reference lubricant which is 794.35mm. Sampel B caused the least wear on the threelower ball bearings used in the tribo-tester experiment. For the engine performance test, sample B has undergone complete combustion with fuel without leaving any carbon deposits on electrodes and insulator tips. In conclusion, the bio based lubricant has improved engine efficiency and reduce wear in a two-stroke engine
Geology, geochemistry and petrotectonic setting of Idanre Granite Complex, Southwestern Nigeria / Akinola Oluwatoyin Olagoke
Get PDFDuring Neoproterozoic, Nigeria like many other Pan-African countries witnessed extensive magmatic activities which resulted in emplacement of granite popularly referred to as Older Granite in Nigeria. The study area is characterized by a large population of this rock type than any other part of Nigeria, so these rocks are investigated in this research. Idanre is underlain by migmatite-gneiss, charnockite and granite. Migmatite form the country rock and are low-lying, charnockite was surrounded by granite, while the granite forms large inselbergs. Three textural types of granite occur in the area, they are coarse-grained granite (undifferentiated) (OGu), porphyritic granite (OGp) and the fine-grained granite (OGf). Analytical results revealed the siliceous nature of the basement rocks, the range of silica contents are migmatite (55.90 - 65.32%), charnockite (60.62 - 63.70%) and granite (62.97 - 74.52%). Geochemical result also showed the granitoids range in composition from alkali granite to granodiorite, they are metaluminous ferroan I-type late orogenic suites with shoshonitic to high-K alkali calcic signatures. Na2O/Al2O3 versus K2O/Al2O3 diagram showed the protolith of the granite rocks have extensive data plot spread within igneous field revealing the granite originated from anatexis of igneous rocks. The occurrence of igneous structures like poikilitic textures, sphene and myrmekite are petrographic evidence of igneous origin for the granite. All the granites exhibit similar geochemical coherence between their trace elements distribution evidenced by similar shape for the chondrite normalized REE pattern. The gneiss units are also characterized by similar geochemical features. All the granite samples showed LREE enrichment, HREE depletion and plagioclase fractionation with evidence from negative Eu anomaly (Eu/Eu*<1). Geochemical appraisal revealed the granitoids are of “within-plate” tectonic setting. Zircon U-Pb geochronology showed migmatite with 1065.1 ± 7.1 Ma age represents the oldest rock in Idanre area. This was subsequently followed by charnockite (590.3 ± 5.3 Ma), fine-grained granite (588.4 ± 5.5 Ma) and porphyritic granite (584.5 ± 5.8 Ma) while the last magmatic episode produced the Undifferentiated granite (581.8 ± 5.5 Ma) which is the youngest member of the suite. 176Hf/177Hf ratios in OGu vary between 0.281724 and 0.281843 with initial 176Hf/177Hf between 0.281715 and 0.281782, ƐHf(t) values range between -22.2 to -23.5 and tDM2 age 2800 ~ 2990 Ma. 176Hf/177Hf ratios in OGp range between 0.281692 and 0.281863, initial Hf values between 0.281683 and 0.281848, ƐHf(t) values between -22.5 to -25.5, tDM2 age range between 2850 ~ 2950 Ma. In OGf, 176Hf/177Hf values range between 0.281712 to 0.281813 with initial values from 0.281708 to 0.281802, ƐHf(t) lies between -22.4 to -25.7 and tDM2 age 2880 ~ 3000 Ma. These tDM2 values all indicated that the inherited zircons were separated from the “Depleted Mantle” around 2.8 ~ 3.0 Ga. Negative ƐHf(t) values symbolized derivation from crustal source, while tDM2 age implied magma source originated during Mesoarchean
The effect of vocal warm-up on voice quality of untrained female singers in Malaysia / Ter Wei Shean
Get PDFProfessional singers and singing teachers regard vocal warm-up as vital. However, very few studies have evaluated this effect quantitatively. This study aimed to evaluate the effect of the vocal warm-up on the singing voice quality through acoustic parameters of Jitter, Shimmer and harmonics-to-noise ratio (HNR) and to assess whether scientific evidence supports the warm-up procedure, whether an untrained singer can benefit from singing vocal warm-up exercises in a similar way as a trained singer and whether the vocal warm-up should be encouraged or bypassed. 40 untrained female singers were recorded twice while uttering the vowel /a/, /o/ and /i/ in two different pitches: Low- A3 (220.0 Hz) and High- C5 (523.2 Hz) for at least five seconds. The recordings were collected before and after a 20 minutes vocal warm-up session. Results showed significant variations in the average values of the parameters measured. A decrease was detected in comparison with the average value of Jitter and Shimmer before and after the vocal warm up, whereas HNR increased. The results of this study provide valid support for the advantageous effect of vocal warm-up on the voice quality of untrained female singers and present acoustic analysis as a valuable and sensitive tool for quantifying this effect. The positive effects of the findings indicated that the vocal warm-up should be encouraged and not bypassed. As for the vowel effect, per cent jitter, per cent shimmer and harmonics-to-noise ratio (HNR) may not be useful for the description of acoustic
differences between vowels
The relationship between mental workload and driving performance of ageing drivers / Nurul Izzah Abd Rahman
Get PDFThe population of ageing drivers is increasing rapidly. As ageing happened, they are exposed to disabilities due to degenerative processes, thus affecting their driving performance. For changes in driving method or design to occur, ageing drivers’ driving tasks need to be monitored, designed and tested. Comprehensive research needs to be conducted to investigate how to integrate mental workload with driving performance of ageing people. Moreover, there has been no study yet that develop a model to predict overall driving performance in Malaysia. Hence, the main objective of this study is to develop and validate a model which quantifies the mental workload on the driving performance of ageing drivers. In this study, the methodology consisted of database observations, survey and on-the-road experimental tasks. For the experimental tasks, the measurements involved were subjective ratings using NASA Task Load Index (NASA TLX), physiological measure using electroencephalogram, number of traffic violations (NTVs), speed variability, and reaction time of peripheral detection. The accident database showed that the accident occurrences appear to be much higher among male drivers. From the survey on 182 drivers, about 60% of ageing drivers have been involved in accidents previously; driving experience has significant association with accident involvement. They have driving difficulties during rain (72%), rush hour (57%) and nighttime (59%). From the experimental tasks, the NASA-Task Load Index scores revealed that the ageing drivers’ subjective workload ratings increased with higher complexity situation. Their mean physical demand score was the highest compared to others in Moderately Complex Situation (MCS) and Very Complex Situation (VCS); scoring 37.25 and 43.50 respectively. Meanwhile, for Electroencephalogram signals’ fluctuation, results showed that situation complexity had significant effects on RPθ and RPα of channel locations FZPZ and O1O2. Both frequencies were lower in VCS compared to MCS. In addition, RPθ and RPα were significantly higher among male drivers compared to female, regardless of the situation complexity and ToT. Findings revealed that the highest mean number of traffic violations was in VCS where it was 35% higher compared to Simple Situation (SS). Furthermore, results showed that the mean speed in SS was significantly higher than MCS (42%) and VCS (38%), while the mean speed variability in MCS was significantly lower than SS (25%) and VCS (35%). The maximum reaction time was in VCS where it was 6% slower than the minimum reaction time obtained in MCS. Regression models were developed to determine Overall Driving Performance Score (ODPS) of each situation complexity based on the strong correlation and linear relationship between mental workload and driving performance elements. The relationship among these variables is significantly linear in SS (R=0.861), MCS (R=0.813) and VCS (R=0.749). All three models have been validated using data from different groups of drivers. The models would be beneficial as a guideline for designers, manufacturers, developers and policy makers in designing better driving environment for ageing drivers. They will be able to integrate safety and transportation to optimize and sustain driving performance while minimizing accident risks for ageing drivers as well as other road users
Influence of diet and abiotic factors on the survival and reproduction of calanoid copepod Pseudodiaptomus annandalei / Fatin Fatihah Abd Aziz
Get PDFThe calanoid copepod, Pseudodiaptomus annandalei, due to its good nutritional value and significance as a natural diet of many tropical fish, is a superior live feed for marine fish larvae. Fish larvae needs a sustainable supply of good quality live feed for optimal growth and survival. Aims of this study were to investigate the effects of (1) marine mircroheterotrophs grown in palm oil mill effluent (POME) as copepod diet and (2) abiotic factors i.e. salinity (ppt), temperature (˚C), pH, photoperiod and light intensity on the survival and nauplii production of P. annandalei. Both biotic and abiotic experiments were conducted with the initial stocking density of fifty copepod nauplii stage I in 250 ml of sterile 15 ppt brackish water and nauplii were cultured in water baths under controlled condition. Each treatment was conducted in triplicates with a completely randomized design. Survival and reproduction of P. annandalei were determined every 2-day intervals for a duration of 14 days. P. annandalei fed on a mixed diet of 75% POME grown Shewanella algae (POME-SA) and 25% POME-grown Aurantiochytrium limacinum (POME-AL) had significantly (p 0.05) but influenced F2 nauplii production. The highest nauplii density was recorded at 15 ppt (103±48.8 nauplii) on day 14. The survival of P. annandalei was affected by temperature (p < 0.05) where 26˚C gave the highest survival (day 8: 85.3±4.7% and day 14: 58.7±9.6%) compared to those cultured at other temperatures (28˚C to 36˚C). In contrast, significant nauplii production recorded at 28˚C (42±12.4 nauplii). The survival of P. annandalei was affected by pH (p < 0.05) where 49.3±3.7% survival was recorded at pH 8 on last day but the nauplii production was not significant among treatments. Photoperiod did not affect the survival and nauplii production of P. annandalei where 82.0±11.4% survival and 11±4.0 nauplii was recorded at 12h light: 12h dark. The light intensity of 4.05 µmol/m2/sec gave the highest survival of P. annandalei (86.7±2.4%) compared to other treatments tested. No variations between treatments were detected for sex ratio and body growth in salinity, pH, photoperiod and light intensity experiments except for feed. At a larger scale experiment (1L tank), the survival of P. annandalei was high and maintained above 70% through experiment. Fatty acid analysis shows that a consortium of POME grown SA and POME-grown AL biomass contained 0.80±0.01% of docohexanoic acid (DHA) whilst P. annandalei fed on this mixed diet contained high amount of arachidonic acid (ARA) (0.91±0.35%), eicosapentaenoic acid (EPA) (4.36±0.02%) and DHA (7.21±0.06%). As conclusion, a mixed diet of POME-grown SA and POME-grown AL is the most suitable diet for mass culturing P. annandalei in captivity, incorporating the optimal culture conditions of 15±1 ppt salinity, 26.0±1.0 oC, pH 7-8, 12h light: 12h dark photoperiod and light intensity of 4.05 µmol/m2/sec
Data mining for structural damage identification using hybrid artificial neural network based algorithm for beam and slab girder / Meisam Gordan
Get PDFOne of the approaches for structural health monitoring (SHM) consists of two major components, i.e. a network of sensors to collect the response data and an extraction method to obtain information on the structural health condition. Data mining (DM) is a novel data extraction technology which can employ for development of inverse analysis. Implementation of DM techniques in different areas of civil engineering has recently given very good results. However, application of DM in SHM is not used as much as expected, thus, many challenges are still ahead. Therefore, it is necessary to develop the applicability of DM in SHM. Hence, the main objective of this research is to address the feasibility and demonstrate the potential of DM in SHM, as well as apply DM technology which includes machine learning, artificial intelligence and statistical methods for damage detection of a lab-scale slab-on-girder bridge and four steel I beams structures using dynamic parameters of structures. To this end, experimental modal analysis of aforesaid structures was carried out by introducing different damage scenarios to generate the modal parameter database. Single-type and multiple-type damage cases were inflicted in the composite bridge structure to measure the first four natural frequencies and corresponding mode shapes of the structure at different locations, while only single-type damage using the first four flexural modes was considered in beam-like structures. The collected datasets were used as inputs for the DM process. In this research, a fault diagnosis methodology based on Cross Industry Standard Process for Data Mining (CRISP-DM) model was proposed for the purpose of damage detection. In the modeling phase, amongst all DM algorithms, the applicability of machine learning, artificial intelligence and statistical data mining techniques were examined using Support Vector Machine (SVM), Artificial Neural Network (ANN) and Classification and Regression Tree (CART) to detect the hidden patterns in vibration data. After evaluating the results of these algorithms, a hybrid Artificial Neural Network-based Imperial Competitive Algorithm (ANN-ICA) was presented in the deployment step of the proposed methodology to identify the structural damage of illustrative structures. According to the obtained results, the pre-developed ANN achieved generally more reliable capability of prediction in compare to SVM and CART. In contrast, CART showed the lowest performance of prediction fitness amongst all the patterns. It was also concluded that the ICA could successfully improve the learning process of the neural network. Therefore, the obtained results through the proposed DM procedure using ANN-ICA (1) confirmed the robustness of the hybrid network in compare to the pre-developed network, and (2) indicated that, the proposed damage identification model can be considered as a precise approach for monitoring the structural condition subjected to vibrational loads